The direct delivery of inhaled antibiotics to the respiratory tract has been a subject of enduring interest among medical practitioners and researchers due to the associated favorable pharmacokinetics.This interest ha...The direct delivery of inhaled antibiotics to the respiratory tract has been a subject of enduring interest among medical practitioners and researchers due to the associated favorable pharmacokinetics.This interest has been particularly pronounced in the context of critically illpatients,wherehealthcare-associatedpulmonary infections represent a significant challenge,driving continued exploration of inhaled antibiotics for intubated patients.Recent high-level evidence has shown a very promising application in the field of ventilator-associated pneumonia (VAP) prevention.^([1]).展开更多
Objective: To investigate the effect of extracorporeal diaphragmatic pacing combined with noninvasive ventilators on the respiratory function and prognosis of chronic obstructive pulmonary disease (COPD) patients. Met...Objective: To investigate the effect of extracorporeal diaphragmatic pacing combined with noninvasive ventilators on the respiratory function and prognosis of chronic obstructive pulmonary disease (COPD) patients. Methods: A total of 50 COPD patients were selected between January 2023 to December 2023 and randomly grouped into an observation group and a control group, with 25 cases. The observation group was given extracorporeal diaphragm pacing combined with a noninvasive ventilator, while the control group was given a conventional treatment mode. After the treatment, the results of each index in the two groups were compared. Results: Compared with the diaphragm function indexes of the two groups, the data of the observation group were more dominant (P < 0.05). The rehospitalization rate of the observation group was lower than that of the control group (P < 0.05). The COPD assessment test (CAT) and mMRC (Modified Medical Research Council) Dyspnoea scale scores after treatment between the two groups were significantly different (P < 0.05). Compared with the control group, the lung function indexes of the observation group were more dominant (P < 0.05). Conclusion: Extracorporeal diaphragmatic pacing combined with a noninvasive ventilator promoted the improvement of the patient’s prognosis and improved their respiratory function.展开更多
Objective:To explore the clinical effect of a non-invasive ventilator combined with conventional therapy in the treatment of patients with chronic obstructive pulmonary disease(COPD)combined with respiratory failure.M...Objective:To explore the clinical effect of a non-invasive ventilator combined with conventional therapy in the treatment of patients with chronic obstructive pulmonary disease(COPD)combined with respiratory failure.Methods:68 patients with COPD combined with respiratory failure treated in our hospital from September 2021 to October 2023 were selected as the research subjects.Using the random number table method,they were divided into a control group and an experimental group of 34 cases each.The control group received conventional symptomatic treatment,and the experimental group received non-invasive ventilator treatment based on the control group.The clinical effects,blood gas indicators(partial pressure of carbon dioxide(PaCO_(2)),partial pressure of oxygen(PaO_(2)),arterial oxygen saturation(SaO_(2))),lung function(forced expiratory volume in 1 second(FEV1),forced vital capacity(FVC),6 min walking distance),complications,and inflammatory factor levels(c-reactive protein(CRP),interleukin-6(IL-6),neutrophil-to-lymphocyte ratio(NLR))of the two groups of patients were observed.Results:(1)The clinical efficacy of the patients in the experimental group(33/97.06%)was more significant as compared with the control group(25/73.53%)(P<0.05);(2)After treatment,the clinical efficacy of the two groups of patients in terms of FEV1,FEV1/FVC,6-minute walking distance,PaO_(2)and SaO_(2)all increased in the experimental group as compared to that of the control group(P<0.05);(3)After treatment,the PaCO_(2),CRP,IL-6,and NLR of the two groups of patients decreased,and the decrease in the experimental group was higher than that of the control group(P<0.05);(4)The patients’complication rate in the experimental group(2/5.88%)was lower as compared to that of the control group(9/26.46%)(P<0.05).Conclusion:Non-invasive ventilators combined with conventional therapy achieved good clinical results in treating patients with COPD and respiratory failure.展开更多
Ventilator-associated pneumonia (VAP) is one of the most important hospital infections in hospitalized patients, which is associated with increased mortality and patient costs. The tracheal tube itself seems to be a m...Ventilator-associated pneumonia (VAP) is one of the most important hospital infections in hospitalized patients, which is associated with increased mortality and patient costs. The tracheal tube itself seems to be a major risk factor for VAP. Contaminated secretions pass through the endotracheal tube and reach the lungs. Also, bacteria form a bacterial biofilm on the tracheal tube and are transferred from there to the lungs. Different tracheal tube designs have been produced to overcome these cases. The purpose of this study is to investigate the effect of an Evac tracheal tube covered with antibiotics and normal on the incidence of pneumonia caused by the ventilator. Research method: 180 patients were randomly intubated in three groups of 60 people with three types of tracheal tubes, Evac and Bactiguard. Clinical examinations, endotracheal tube aspiration culture, and chest radiography were obtained from the patients and the incidence of VAP was calculated based on the CPIS standard. The relationship between the type of endotracheal tube and the incidence of VAP and the length of stay in the intensive care unit (ICU) and being discharged alive from the ICU were investigated. Findings and conclusions: The average incidence of VAP for the group of patients intubated with a conventional tracheal tube was 50%, EVAC was 45% and Bactiguard was 40%. The results showed that there is no significant relationship between the incidence of ventilator-induced pneumonia and the type of tracheal tube. The incidence of ventilator-induced pneumonia was not significantly reduced by suctioning subglottic secretions and Bactiguard tracheal tubes. It seems that using one method alone is not effective in reducing ventilator-induced pneumonia.展开更多
Objective:To evaluate the efficacy of emergency ventilator therapy in severe acute left heart failure.Methods:A total of 75 patients with severe acute left ventricular heart failure who were admitted to the hospital f...Objective:To evaluate the efficacy of emergency ventilator therapy in severe acute left heart failure.Methods:A total of 75 patients with severe acute left ventricular heart failure who were admitted to the hospital from July 2020 to July 2023 were randomly divided into two groups.Group A received additional emergency ventilator treatment,and group B received conventional treatment.The efficacy was compared.Results:The curative effect of patients with severe acute left heart failure in group A was higher than that in group B(P<0.05);all blood gas indicators in group A were better than those in group B(P<0.05);all vital signs indicators in group A were better than those in group B(P<0.05);group A was more satisfied with the treatment of severe acute left ventricular heart failure than group B(P<0.05).Conclusion:Patients with severe acute left heart failure who receive emergency ventilator treatment can stabilize vital signs,improve blood oxygen supply,and enhance curative effect.展开更多
BACKGROUND The optimal treatment for heart failure(HF)is a combination of appropriate medications.Controlling the disease using only medical therapy is difficult in patients with HF,severe hypercapnia,and desaturation...BACKGROUND The optimal treatment for heart failure(HF)is a combination of appropriate medications.Controlling the disease using only medical therapy is difficult in patients with HF,severe hypercapnia,and desaturation.These patients should first receive ventilator support followed by pulmonary rehabilitation(PR).CASE SUMMARY We report two cases in which arterial blood gas(ABG)improved and PR was possible with appropriate ventilator support.Two patients with extreme obesity complaining of worsening dyspnea–a 47-year-old woman and a 36-year-old man both diagnosed with HF–were hospitalized because of severe hypercapnia and hypoxia.Despite proper medical treatment,hypercapnia and desaturation resolved in neither case,and both patients were transferred to the rehabilitation department for PR.At the time of the first consultation,the patients were bedridden because of dyspnea.Oxygen demand was successfully reduced once noninvasive ventilation was initiated.As the patients’dyspnea gradually improved to the point where they could be weaned off the ventilator during the daytime,they started engaging in functional training and aerobic exercise.After 4 mo of followup,both patients were able to perform activities of daily living and maintain their lower body weight and normalized ABG levels.CONCLUSION Symptoms of patients with obesity and HF may improve once ABG levels are normalized through ventilator support and implementation of PR.展开更多
BACKGROUND:We sought to evaluate the risk factors for developing ventilator-associated pneumonia(VAP)and whether the location of intubation posed a risk in trauma patients.METHODS:Data were retrospectively reviewed fo...BACKGROUND:We sought to evaluate the risk factors for developing ventilator-associated pneumonia(VAP)and whether the location of intubation posed a risk in trauma patients.METHODS:Data were retrospectively reviewed for adult trauma patients requiring intubation for>48 hours,admitted between 2010 and 2013.Patients’demographics,clinical presentations and outcomes were compared according to intubation location(prehospital intubation[PHI]vs.trauma room[TRI])and presence vs.absence of VAP.Multivariate regression analysis was performed to identify predictors of VAP.RESULTS:Of 471 intubated patients,332 patients met the inclusion criteria(124 had PHI and208 had TRI)with a mean age of 30.7±14.8 years.PHI group had lower GCS(P=0.001),respiratory rate(P=0.001),and higher frequency of head(P=0.02)and chest injuries(P=0.04).The rate of VAP in PHI group was comparable to the TRI group(P=0.60).Patients who developed VAP were 6 years older,had significantly lower GCS and higher ISS,head AIS,and higher rates of polytrauma.The overall mortality was 7.5%,and was not associated with intubation location or pneumonia rates.In the early-VAP group,gram-positive pathogens were more common,while gram-negative microorganisms were more frequently encountered in the late VAP group.Logistic regression analysis and modeling showed that the impact of the location of intubation in predicting the risk of VAP appeared only when chest injury was included in the models.CONCLUSION:In trauma,the risk of developing VAP is multifactorial.However,the location of intubation and presence of chest injury could play an important role.展开更多
OSAHS(Obstructive Sleep Apnea Hypopnea Syndrome)is a respiratory disease mainly characterized by limited and repeated pauses of breathing in sleep.Currently,the optimal treatment is to apply CPAP(Continuous Positive A...OSAHS(Obstructive Sleep Apnea Hypopnea Syndrome)is a respiratory disease mainly characterized by limited and repeated pauses of breathing in sleep.Currently,the optimal treatment is to apply CPAP(Continuous Positive Airway Pressure)ventilation on the upper airway of the patient through a household respiratory machine.However,if the ventilator mask is designed improperly,it might cause the residue and repeated inhalation of CO2,which will exert an adverse impact on the therapeutic effect.Present research numerically analyzed the CO2 transportation inside a commercial ventilator mask(Mirage SoftGel,ResMed,Australia)based on the reconstructed 3D numerical model of a volunteer's face and performed the improved design of the ventilator mask in terms of the CO2 residual concentration below the nostrils.The fluid dynamic analyses showed that at the end time of expiratory,the CO2 residual concentration below the nostrils is close to 4%.To improve the therapeutic effect,we changed the position of the exhaust holes and found that by moving the exhaust holes to the bottom of the ventilator mask,the CO2 residual concentration below the nostrils would be reduced to no more than 1%.This study established a near physiological computational model and provided a new method for the individualized design of the commercial ventilator mask.展开更多
AIM: To determine the incidence, etiology, risk factors and outcome of ventilator-associated pneumonia(VAP) in patients undergoing orthotopic liver transplantation(OLT).METHODS: This retrospective study considered 242...AIM: To determine the incidence, etiology, risk factors and outcome of ventilator-associated pneumonia(VAP) in patients undergoing orthotopic liver transplantation(OLT).METHODS: This retrospective study considered 242 patients undergoing deceased donor OLT. VAP was diagnosed according to clinical and microbiological criteria. RESULTS: VAP occurred in 18(7.4%) patients, with an incidence of 10 per 1000 d of mechanical ventilation(MV). Isolated bacterial etiologic agents were mainly Enterobacteriaceae(79%). Univariate logistic analysis showed that model for end-stage liver disease(MELD) score, pre-operative hospitalization, treatment with terlipressin, Child-Turcotte-Pugh score, days of MV and red cell transfusion were risk factors for VAP. Multivariateanalysis, considering significant risk factors in univariate analysis, demonstrated that pneumonia was strongly associated with terlipressin usage, pre-operative hospitalization, days of MV and red cell transfusion. Mortality rate was 22% in the VAP group vs 4% in the group without VAP. CONCLUSION: Our data suggest that VAP is an important cause of nosocomial infection during postoperative period in OLT patients. MELD score was a significant risk factor in univariate analysis. Multiple transfusions, treatment with terlipressin, preoperative hospitalization rather than called to the hospital while at home and days of MV constitute important risk factors for VAP development.展开更多
Objective： Ventilator associated pneumonia （VAP） has been shown to be associated with significant morbidity and mortality（ Chastre and Fagon, 2002; klompas, 2007） among mechanically venti- lated patients in the i...Objective： Ventilator associated pneumonia （VAP） has been shown to be associated with significant morbidity and mortality（ Chastre and Fagon, 2002; klompas, 2007） among mechanically venti- lated patients in the intensive care unit （ICU）, with the incidence ranging from 9% to 27% ; crude mortality ranges from 25% to 50%.1-3 A meta-analysis of published studies was undertaken to combine information regarding the effect of subglottic secretion drainage （SSD） on the incidence of ventilated associated pneumonia in adult ICU patients. Methods： Reports of studies on SSD were identified by searching the PUBMED, EMBASE, and COCHRANCE LIBRARY databases （December 30, 2010）. Randomized trials of SSD compared to usual care in adult mechanically ventilated ICU patients were included in this meta-analysis. Results： Ten RCTs with 2,314 patients were identified. SSD significantly reduced the incidence of VAP [ relative risk （RR） =0.52, 95% confidence interval （C/）： 0.42-0.64, P〈0.000 01]. When SSD was compared with the control groups, the overall RR for ICU mortality was 1.00 （95% CI, 0.84-1.19） and for hospital mortality was 0.95 （95% CI, 0. 80-1.13）. Overall, the subglottic drainage effect on the days of mechanical ventilation was -1.52 days （95% CI, -2.94 to -0.11） and on the ICU length of stay （LOS） was -0.81days （95% CI, -2.33 to -0.7）. Conclusions： In this meta-analysis, when an endotracheal tube （ETT） with SSD was compared with an ETT without SSD, there was a highly significant reduction in the VAP rate of approxi- mately 50%. Time on mechanical ventilation （MV） and the ICU LOS may be reduced, but no reduction in ICU or hospital mortality has been observed in published trials,展开更多
Expiratory flow limitation(EFL), that is the inability of expiratory flow to increase in spite of an increase of the driving pressure, is a common and unrecognized occurrence during mechanical ventilation in a variety...Expiratory flow limitation(EFL), that is the inability of expiratory flow to increase in spite of an increase of the driving pressure, is a common and unrecognized occurrence during mechanical ventilation in a variety of intensive care unit conditions. Recent evidence suggests that the presence of EFL is associated with an increase in mortality, at least in acute respiratory distress syndrome(ARDS) patients, and in pulmonary complications in patients undergoing surgery. EFL is a major cause of intrinsic positive end-expiratory pressure(PEEPi), which in ARDS patients is heterogeneously distributed, with a consequent increase of ventilation/perfusion mismatch and reduction of arterial oxygenation. Airway collapse is frequently concomitant to the presence of EFL.When airways close and reopen during tidal ventilation, abnormally high stresses are generated that can damage the bronchiolar epithelium and uncouple small airways from the alveolar septa, possibly generating the small airways abnormalities detected at autopsy in ARDS. Finally, the high stresses and airway distortion generated downstream the choke points may contribute to parenchymal injury, but this possibility is still unproven. PEEP application can abolish EFL, decrease PEEPi heterogeneity, and limit recruitment/derecruitment.Whether increasing PEEP up to EFL disappearance is a useful criterion for PEEP titration can only be determined by future studies.展开更多
Resource-scarce regions with serious COVID-19 outbreaks do not have enough ventilators to support critically ill patients,and these shortages are especially devastating in developing countries.To help alleviate this s...Resource-scarce regions with serious COVID-19 outbreaks do not have enough ventilators to support critically ill patients,and these shortages are especially devastating in developing countries.To help alleviate this strain,we have designed and tested the accessible low-barrier in vivo-validated economical ventilator(ALIVE Vent),a COVID-19-inspired,cost-effective,open-source,in vivo-validated solution made from commercially available components.The ALIVE Vent operates using compressed oxygen and air to drive inspiration,while two solenoid valves ensure one-way flow and precise cycle timing.The device was functionally tested and profiled using a variable resistance and compliance artificial lung and validated in anesthetized large animals.Our functional test results revealed its effective operation under a wide variety of ventilation conditions defined by the American Association of Respiratory Care guidelines for ventilator stockpiling.The large animal test showed that our ventilator performed similarly if not better than a standard ventilator in maintaining optimal ventilation status.The FiO2,respiratory rate,inspiratory to expiratory time ratio,positive-end expiratory pressure,and peak inspiratory pressure were successfully maintained within normal,clinically validated ranges,and the animals were recovered without any complications.In regions with limited access to ventilators,the ALIVE Vent can help alleviate shortages,and we have ensured that all used materials are publicly available.While this pandemic has elucidated enormous global inequalities in healthcare,innovative,cost-effective solutions aimed at reducing socio-economic barriers,such as the ALIVE Vent,can help enable access to prompt healthcare and life saving technology on a global scale and beyond COVID-19.展开更多
Considering four different climate zones in China, an investigation on the choice of heat recovery ventilator for the buildings with little moisture emissions is carried out. The annual composition of energy consumpti...Considering four different climate zones in China, an investigation on the choice of heat recovery ventilator for the buildings with little moisture emissions is carried out. The annual composition of energy consumption of air intake for per unitary air ventilation flow rate is evaluated by employing the testing data of climatic parameters in eight selected cities. The analysis shows that the total heat recovery is suitable in a controlled ventilation system with air humidity controlled during heating period of all the climates. For the building without air humidity controlled in winter, the sensible heat recovery ventilators can be used in severe cold and cold regions, and total heat recovery systems are more suitable for energy saving in hot summer and cold winter and hot summer and warm winter regions.展开更多
BACKGROUND Patients with cancer have several risk factors for developing respiratory failure requiring mechanical ventilation(MV).The emergence of multidrug resistant bacteria(MDRB)has become a public health problem,c...BACKGROUND Patients with cancer have several risk factors for developing respiratory failure requiring mechanical ventilation(MV).The emergence of multidrug resistant bacteria(MDRB)has become a public health problem,creating a new burden on medical care in hospitals,particularly for patients admitted to the intensive care unit(ICU).AIM To describe risk factors for ventilator-acquired pneumonia(VAP)in patients with cancer and to evaluate the impact of MDRB.METHODS A retrospective study was performed from January 2016 to December 2018 at a cancer referral center in Mexico City,which included all patients who were admitted to the ICU and required MV≥48 h.They were classified as those who developed VAP versus those who did not;pathogens isolated,including MDRB.Clinical evolution at 60-d was assessed.Descriptive analysis was carried out;comparison was performed between VAP vs non-VAP and MDRB vs non-MDRB.RESULTS Two hundred sixty-three patients were included in the study;mean age was 51.9 years;52.1%were male;68.4%had solid tumors.There were 32 episodes of VAP with a rate of 12.2%;11.5 episodes/1000 ventilation-days.The most frequent bacteria isolated were the following:Klebsiella spp.[n=9,four were Extended-Spectrum Beta-Lactamase(ESBL)producers,one was Carbapenem-resistant(CR)];Escherichia coli(n=5,one was ESBL),and Pseudomonas aeruginosa(n=8,two were CR).One Methicillin-susceptible Staphylococcus aureus was identified.In multivariate analysis,the sole risk factor associated for VAP was length of ICU stay(OR=1.1;95%CI:1.03-1.17;P=0.003).Sixty-day mortality was 53%in VAP and 43%without VAP(P=0.342).There was not higher mortality in those patients with MDRB.CONCLUSION This study highlights the high percentage of Gram-negative bacteria,which allows the initiation of empiric antibiotic coverage for these pathogens.In this retrospective,single center,observational study,MDRB VAP was not directly linked to increased mortality at 60 days.展开更多
Objective:To observe the application effect of non-invasive ventilator in the treatment of acute heart failure merged with respiratory failure in ICU.Methods:A total of 80 patients with acute heart failure merged with...Objective:To observe the application effect of non-invasive ventilator in the treatment of acute heart failure merged with respiratory failure in ICU.Methods:A total of 80 patients with acute heart failure merged with respiratory failure who were admitted in ICU from January, 2015 to January, 2016 were included in the study and randomized into the observation group and the control group with 40 cases in each group. The patients in the two groups were given routine treatments after admission. On this basis, the patients in the observation group were given non-invasive ventilator. The patients in the control group were given continuous low flow oxygen inhalation. PaO2, pH, PaCO2, SaO2, and PaO2/FiO2 before and after treatment between the two groups were compared. The serum NT-pro BNP and cTnI levels before treatment, 24 h and 48 h after treatment in the two groups were compared.Results:The comparison of PaO2, pH, PaCO2, SaO2, and PaO2/FiO2 before treatment between the two groups was not statistically significant. PaO2, pH, SaO2, and PaO2/FiO2 after treatment in the two groups were significantly elevated, while PaCO2 was significantly reduced when compared with before treatment. PaO2, pH, SaO2, and PaO2/FiO2 after treatment in the observation group were significantly higher than those in the control group, while PaCO2 was significantly lower than that in the control group. The comparison of NT-pro BNP and cTnI levels before treatment between the two groups was not statistically significant. NT-pro BNP and cTnI levels 12 h and 24 h after treatment in the two groups were significantly elevated when compared with before treatment. NT-pro BNP and cTnI levels 12 h and 24 h after treatment in the observation group were significantly lower than those in the control group.Conclusions:Non-invasive ventilator in the treatment of acute heart failure merged with respiratory failure can effectively improve the ventilation function, reduce NT-pro BNP and cTnI levels, and is of great significance in enhancing the rescued effect.展开更多
This review, based on relevant published evidence and the authors` clinical experience, presents how to evaluate a patient with acute respiratory failure requiring ventilatory support. This patient must be carefully e...This review, based on relevant published evidence and the authors` clinical experience, presents how to evaluate a patient with acute respiratory failure requiring ventilatory support. This patient must be carefully evaluated by nurses, physiotherapists, respiratory care practitioners and physicians regarding the elucidation of the cause of the acute episode of respiratory failure by means of physical examination with the measurement of respiratory parameters and assessment of arterial blood gases analysis to make a correct respiratory diagnosis. After the initial evaluation, the patient must quickly receive adequate oxygen and ventilatory support that has to be carefully monitored until its discontinuation. When available, a noninvasive ventilation trial must be done in patients presenting desaturation during oxygen mask and or PaCO2 retention, especially in cases of cardiogenic pulmonary edema and severe exacerbation of chronic obstructive pulmonary disease. In cases of noninvasive ventilation trial-failure, endotracheal intubation and invasive protective mechanical ventilation must be promptly initiated. In severe ARDS patients, low tidal ventilation, higher PEEP levels, prone positioning and recruitment maneuvers with adequate PEEP titration should be used. Recently, new modes of ventilation should allow a better patient-ventilator interaction or synchrony permitting a sufficient unloading of respiratory muscles and increase patient comfort. Patients with chronic obstructive pulmonary disease may be considered for a trial for early extubation to noninvasive positive pressure ventilation in centers with extensive experience in noninvasive positive pressure ventilation.展开更多
Objective: To investigate the effect of Shenqi Fuzheng Injection combined with naloxone and BiPAP ventilator on serum inflammatory factors, immune function and blood gas analysis indexes in treatment of AECOPD with ty...Objective: To investigate the effect of Shenqi Fuzheng Injection combined with naloxone and BiPAP ventilator on serum inflammatory factors, immune function and blood gas analysis indexes in treatment of AECOPD with type Ⅱ respiratory failure. Methods: A total of 82 patients with AECOPD and type Ⅱ respiratory failure were divided into control group (n=40) and observation group (n=42) according to random data table, patients in the control group received naloxone and BiPAP ventilator therapy, and observation group patients were treated with Shenqi Fuzheng Injection on the basis of control group. The levels of serum inflammatory factors, immune function and blood gas analysis indexes were compared between the two groups before and after treatment. Results: There were no significant difference in levels of CRP, TNF-α, IL-6, CD3+, CD4+, CD8+, CD4+/CD8+, PaO2, PaCO2, SaO2 and pH before and after treatment in the two groups. After treatment, the levels of CRP, TNF-α, IL-6, CD8+and PaCO2 in two groups were significantly lower than those in same group before treatment, moreover observation group was significantly lower than control group;and levels of CRP, TNF-α, IL-6, CD8+ and PaCO2 in the observation group was significantly lower than those of the control group, the difference was statistically significant;When compared with the group before treatment, CD3+, CD4+, CD4+/CD8+, PaO2, SaO2 and pH levels of both groups after treatment were significantly increased, and the level of each index of observation group after treatment were significantly higher than the control group, the difference was statistically significant. Conclusion: The clinical effect of Shenqi Fuzheng Injection Combined with naloxone and BiPAP ventilator in treatment of AECOPD with type II respiratory failure is significant, can effectively reduce the body's inflammatory reaction, improve immune function, regulate blood gas analysis index, with a certain clinical value.展开更多
Objective:To analyze the factors of flatulence in patients treated with non-invasive ventilator and summarize practical and effective nursing measures.Methods:From July 2020 to June 2021,40 patients who complained of ...Objective:To analyze the factors of flatulence in patients treated with non-invasive ventilator and summarize practical and effective nursing measures.Methods:From July 2020 to June 2021,40 patients who complained of flatulence after using non-invasive ventilator were analyzed.Results:20 cases of abdominal distension were caused by the habit of breathing with their mouth open,10 cases of abdominal distention were caused by liking to eat soup,10 cases of abdominal distention were caused by long-term bed-in-bed activity reduced gastrointestinal peristalsis constipation.Conclusion:We should investigate the causes causing gastrointestinal flatulence with the use of non-invasive ventilators,intervene in advance,boost patient comfort,collaborate with therapy,and improve the therapeutic result.展开更多
A study was carried out to control the noise produced by the ventilators at the Luling coalmine, which had caused serious noise pollution to the residents living around the mine for a long time. The main noise source ...A study was carried out to control the noise produced by the ventilators at the Luling coalmine, which had caused serious noise pollution to the residents living around the mine for a long time. The main noise source was found to be the dynamic noise at the outlet of the diffuser. The frequency of its peak value was 250 Hz. A special brick with a resonant frequency of 250 Hz was designed to eliminate this noise. The diffusion of a lower frequency noise has been successfully controlled by the installation of a noise-eliminating tower above the diffuser outlet. The detection results show that the noise in the nearby residential area has been lowered to an average 55.3dB(A) in the daytime from 69.8dB(A) and to 48.4dB(A) at night from 65.8dB(A).展开更多
文摘The direct delivery of inhaled antibiotics to the respiratory tract has been a subject of enduring interest among medical practitioners and researchers due to the associated favorable pharmacokinetics.This interest has been particularly pronounced in the context of critically illpatients,wherehealthcare-associatedpulmonary infections represent a significant challenge,driving continued exploration of inhaled antibiotics for intubated patients.Recent high-level evidence has shown a very promising application in the field of ventilator-associated pneumonia (VAP) prevention.^([1]).
文摘Objective: To investigate the effect of extracorporeal diaphragmatic pacing combined with noninvasive ventilators on the respiratory function and prognosis of chronic obstructive pulmonary disease (COPD) patients. Methods: A total of 50 COPD patients were selected between January 2023 to December 2023 and randomly grouped into an observation group and a control group, with 25 cases. The observation group was given extracorporeal diaphragm pacing combined with a noninvasive ventilator, while the control group was given a conventional treatment mode. After the treatment, the results of each index in the two groups were compared. Results: Compared with the diaphragm function indexes of the two groups, the data of the observation group were more dominant (P < 0.05). The rehospitalization rate of the observation group was lower than that of the control group (P < 0.05). The COPD assessment test (CAT) and mMRC (Modified Medical Research Council) Dyspnoea scale scores after treatment between the two groups were significantly different (P < 0.05). Compared with the control group, the lung function indexes of the observation group were more dominant (P < 0.05). Conclusion: Extracorporeal diaphragmatic pacing combined with a noninvasive ventilator promoted the improvement of the patient’s prognosis and improved their respiratory function.
文摘Objective:To explore the clinical effect of a non-invasive ventilator combined with conventional therapy in the treatment of patients with chronic obstructive pulmonary disease(COPD)combined with respiratory failure.Methods:68 patients with COPD combined with respiratory failure treated in our hospital from September 2021 to October 2023 were selected as the research subjects.Using the random number table method,they were divided into a control group and an experimental group of 34 cases each.The control group received conventional symptomatic treatment,and the experimental group received non-invasive ventilator treatment based on the control group.The clinical effects,blood gas indicators(partial pressure of carbon dioxide(PaCO_(2)),partial pressure of oxygen(PaO_(2)),arterial oxygen saturation(SaO_(2))),lung function(forced expiratory volume in 1 second(FEV1),forced vital capacity(FVC),6 min walking distance),complications,and inflammatory factor levels(c-reactive protein(CRP),interleukin-6(IL-6),neutrophil-to-lymphocyte ratio(NLR))of the two groups of patients were observed.Results:(1)The clinical efficacy of the patients in the experimental group(33/97.06%)was more significant as compared with the control group(25/73.53%)(P<0.05);(2)After treatment,the clinical efficacy of the two groups of patients in terms of FEV1,FEV1/FVC,6-minute walking distance,PaO_(2)and SaO_(2)all increased in the experimental group as compared to that of the control group(P<0.05);(3)After treatment,the PaCO_(2),CRP,IL-6,and NLR of the two groups of patients decreased,and the decrease in the experimental group was higher than that of the control group(P<0.05);(4)The patients’complication rate in the experimental group(2/5.88%)was lower as compared to that of the control group(9/26.46%)(P<0.05).Conclusion:Non-invasive ventilators combined with conventional therapy achieved good clinical results in treating patients with COPD and respiratory failure.
文摘Ventilator-associated pneumonia (VAP) is one of the most important hospital infections in hospitalized patients, which is associated with increased mortality and patient costs. The tracheal tube itself seems to be a major risk factor for VAP. Contaminated secretions pass through the endotracheal tube and reach the lungs. Also, bacteria form a bacterial biofilm on the tracheal tube and are transferred from there to the lungs. Different tracheal tube designs have been produced to overcome these cases. The purpose of this study is to investigate the effect of an Evac tracheal tube covered with antibiotics and normal on the incidence of pneumonia caused by the ventilator. Research method: 180 patients were randomly intubated in three groups of 60 people with three types of tracheal tubes, Evac and Bactiguard. Clinical examinations, endotracheal tube aspiration culture, and chest radiography were obtained from the patients and the incidence of VAP was calculated based on the CPIS standard. The relationship between the type of endotracheal tube and the incidence of VAP and the length of stay in the intensive care unit (ICU) and being discharged alive from the ICU were investigated. Findings and conclusions: The average incidence of VAP for the group of patients intubated with a conventional tracheal tube was 50%, EVAC was 45% and Bactiguard was 40%. The results showed that there is no significant relationship between the incidence of ventilator-induced pneumonia and the type of tracheal tube. The incidence of ventilator-induced pneumonia was not significantly reduced by suctioning subglottic secretions and Bactiguard tracheal tubes. It seems that using one method alone is not effective in reducing ventilator-induced pneumonia.
文摘Objective:To evaluate the efficacy of emergency ventilator therapy in severe acute left heart failure.Methods:A total of 75 patients with severe acute left ventricular heart failure who were admitted to the hospital from July 2020 to July 2023 were randomly divided into two groups.Group A received additional emergency ventilator treatment,and group B received conventional treatment.The efficacy was compared.Results:The curative effect of patients with severe acute left heart failure in group A was higher than that in group B(P<0.05);all blood gas indicators in group A were better than those in group B(P<0.05);all vital signs indicators in group A were better than those in group B(P<0.05);group A was more satisfied with the treatment of severe acute left ventricular heart failure than group B(P<0.05).Conclusion:Patients with severe acute left heart failure who receive emergency ventilator treatment can stabilize vital signs,improve blood oxygen supply,and enhance curative effect.
基金Supported by The“Research Base Construction Fund Support Program”funded by Jeonbuk National University in 2021.
文摘BACKGROUND The optimal treatment for heart failure(HF)is a combination of appropriate medications.Controlling the disease using only medical therapy is difficult in patients with HF,severe hypercapnia,and desaturation.These patients should first receive ventilator support followed by pulmonary rehabilitation(PR).CASE SUMMARY We report two cases in which arterial blood gas(ABG)improved and PR was possible with appropriate ventilator support.Two patients with extreme obesity complaining of worsening dyspnea–a 47-year-old woman and a 36-year-old man both diagnosed with HF–were hospitalized because of severe hypercapnia and hypoxia.Despite proper medical treatment,hypercapnia and desaturation resolved in neither case,and both patients were transferred to the rehabilitation department for PR.At the time of the first consultation,the patients were bedridden because of dyspnea.Oxygen demand was successfully reduced once noninvasive ventilation was initiated.As the patients’dyspnea gradually improved to the point where they could be weaned off the ventilator during the daytime,they started engaging in functional training and aerobic exercise.After 4 mo of followup,both patients were able to perform activities of daily living and maintain their lower body weight and normalized ABG levels.CONCLUSION Symptoms of patients with obesity and HF may improve once ABG levels are normalized through ventilator support and implementation of PR.
文摘BACKGROUND:We sought to evaluate the risk factors for developing ventilator-associated pneumonia(VAP)and whether the location of intubation posed a risk in trauma patients.METHODS:Data were retrospectively reviewed for adult trauma patients requiring intubation for>48 hours,admitted between 2010 and 2013.Patients’demographics,clinical presentations and outcomes were compared according to intubation location(prehospital intubation[PHI]vs.trauma room[TRI])and presence vs.absence of VAP.Multivariate regression analysis was performed to identify predictors of VAP.RESULTS:Of 471 intubated patients,332 patients met the inclusion criteria(124 had PHI and208 had TRI)with a mean age of 30.7±14.8 years.PHI group had lower GCS(P=0.001),respiratory rate(P=0.001),and higher frequency of head(P=0.02)and chest injuries(P=0.04).The rate of VAP in PHI group was comparable to the TRI group(P=0.60).Patients who developed VAP were 6 years older,had significantly lower GCS and higher ISS,head AIS,and higher rates of polytrauma.The overall mortality was 7.5%,and was not associated with intubation location or pneumonia rates.In the early-VAP group,gram-positive pathogens were more common,while gram-negative microorganisms were more frequently encountered in the late VAP group.Logistic regression analysis and modeling showed that the impact of the location of intubation in predicting the risk of VAP appeared only when chest injury was included in the models.CONCLUSION:In trauma,the risk of developing VAP is multifactorial.However,the location of intubation and presence of chest injury could play an important role.
基金We acknowledge the National Natural Science Foundation of China for supporting the project via the grant number 11472062 and 11002034.
文摘OSAHS(Obstructive Sleep Apnea Hypopnea Syndrome)is a respiratory disease mainly characterized by limited and repeated pauses of breathing in sleep.Currently,the optimal treatment is to apply CPAP(Continuous Positive Airway Pressure)ventilation on the upper airway of the patient through a household respiratory machine.However,if the ventilator mask is designed improperly,it might cause the residue and repeated inhalation of CO2,which will exert an adverse impact on the therapeutic effect.Present research numerically analyzed the CO2 transportation inside a commercial ventilator mask(Mirage SoftGel,ResMed,Australia)based on the reconstructed 3D numerical model of a volunteer's face and performed the improved design of the ventilator mask in terms of the CO2 residual concentration below the nostrils.The fluid dynamic analyses showed that at the end time of expiratory,the CO2 residual concentration below the nostrils is close to 4%.To improve the therapeutic effect,we changed the position of the exhaust holes and found that by moving the exhaust holes to the bottom of the ventilator mask,the CO2 residual concentration below the nostrils would be reduced to no more than 1%.This study established a near physiological computational model and provided a new method for the individualized design of the commercial ventilator mask.
文摘AIM: To determine the incidence, etiology, risk factors and outcome of ventilator-associated pneumonia(VAP) in patients undergoing orthotopic liver transplantation(OLT).METHODS: This retrospective study considered 242 patients undergoing deceased donor OLT. VAP was diagnosed according to clinical and microbiological criteria. RESULTS: VAP occurred in 18(7.4%) patients, with an incidence of 10 per 1000 d of mechanical ventilation(MV). Isolated bacterial etiologic agents were mainly Enterobacteriaceae(79%). Univariate logistic analysis showed that model for end-stage liver disease(MELD) score, pre-operative hospitalization, treatment with terlipressin, Child-Turcotte-Pugh score, days of MV and red cell transfusion were risk factors for VAP. Multivariateanalysis, considering significant risk factors in univariate analysis, demonstrated that pneumonia was strongly associated with terlipressin usage, pre-operative hospitalization, days of MV and red cell transfusion. Mortality rate was 22% in the VAP group vs 4% in the group without VAP. CONCLUSION: Our data suggest that VAP is an important cause of nosocomial infection during postoperative period in OLT patients. MELD score was a significant risk factor in univariate analysis. Multiple transfusions, treatment with terlipressin, preoperative hospitalization rather than called to the hospital while at home and days of MV constitute important risk factors for VAP development.
文摘Objective： Ventilator associated pneumonia （VAP） has been shown to be associated with significant morbidity and mortality（ Chastre and Fagon, 2002; klompas, 2007） among mechanically venti- lated patients in the intensive care unit （ICU）, with the incidence ranging from 9% to 27% ; crude mortality ranges from 25% to 50%.1-3 A meta-analysis of published studies was undertaken to combine information regarding the effect of subglottic secretion drainage （SSD） on the incidence of ventilated associated pneumonia in adult ICU patients. Methods： Reports of studies on SSD were identified by searching the PUBMED, EMBASE, and COCHRANCE LIBRARY databases （December 30, 2010）. Randomized trials of SSD compared to usual care in adult mechanically ventilated ICU patients were included in this meta-analysis. Results： Ten RCTs with 2,314 patients were identified. SSD significantly reduced the incidence of VAP [ relative risk （RR） =0.52, 95% confidence interval （C/）： 0.42-0.64, P〈0.000 01]. When SSD was compared with the control groups, the overall RR for ICU mortality was 1.00 （95% CI, 0.84-1.19） and for hospital mortality was 0.95 （95% CI, 0. 80-1.13）. Overall, the subglottic drainage effect on the days of mechanical ventilation was -1.52 days （95% CI, -2.94 to -0.11） and on the ICU length of stay （LOS） was -0.81days （95% CI, -2.33 to -0.7）. Conclusions： In this meta-analysis, when an endotracheal tube （ETT） with SSD was compared with an ETT without SSD, there was a highly significant reduction in the VAP rate of approxi- mately 50%. Time on mechanical ventilation （MV） and the ICU LOS may be reduced, but no reduction in ICU or hospital mortality has been observed in published trials,
文摘Expiratory flow limitation(EFL), that is the inability of expiratory flow to increase in spite of an increase of the driving pressure, is a common and unrecognized occurrence during mechanical ventilation in a variety of intensive care unit conditions. Recent evidence suggests that the presence of EFL is associated with an increase in mortality, at least in acute respiratory distress syndrome(ARDS) patients, and in pulmonary complications in patients undergoing surgery. EFL is a major cause of intrinsic positive end-expiratory pressure(PEEPi), which in ARDS patients is heterogeneously distributed, with a consequent increase of ventilation/perfusion mismatch and reduction of arterial oxygenation. Airway collapse is frequently concomitant to the presence of EFL.When airways close and reopen during tidal ventilation, abnormally high stresses are generated that can damage the bronchiolar epithelium and uncouple small airways from the alveolar septa, possibly generating the small airways abnormalities detected at autopsy in ARDS. Finally, the high stresses and airway distortion generated downstream the choke points may contribute to parenchymal injury, but this possibility is still unproven. PEEP application can abolish EFL, decrease PEEPi heterogeneity, and limit recruitment/derecruitment.Whether increasing PEEP up to EFL disappearance is a useful criterion for PEEP titration can only be determined by future studies.
基金the National Institutes of Health(NIH R01 HL089315-01 and NIH R01 HL152155,YJW)the Thoracic Surgery Foundation Resident Research Fellowship(YZ)the National Science Foundation Graduate Research Fellowship Program(AMI).
文摘Resource-scarce regions with serious COVID-19 outbreaks do not have enough ventilators to support critically ill patients,and these shortages are especially devastating in developing countries.To help alleviate this strain,we have designed and tested the accessible low-barrier in vivo-validated economical ventilator(ALIVE Vent),a COVID-19-inspired,cost-effective,open-source,in vivo-validated solution made from commercially available components.The ALIVE Vent operates using compressed oxygen and air to drive inspiration,while two solenoid valves ensure one-way flow and precise cycle timing.The device was functionally tested and profiled using a variable resistance and compliance artificial lung and validated in anesthetized large animals.Our functional test results revealed its effective operation under a wide variety of ventilation conditions defined by the American Association of Respiratory Care guidelines for ventilator stockpiling.The large animal test showed that our ventilator performed similarly if not better than a standard ventilator in maintaining optimal ventilation status.The FiO2,respiratory rate,inspiratory to expiratory time ratio,positive-end expiratory pressure,and peak inspiratory pressure were successfully maintained within normal,clinically validated ranges,and the animals were recovered without any complications.In regions with limited access to ventilators,the ALIVE Vent can help alleviate shortages,and we have ensured that all used materials are publicly available.While this pandemic has elucidated enormous global inequalities in healthcare,innovative,cost-effective solutions aimed at reducing socio-economic barriers,such as the ALIVE Vent,can help enable access to prompt healthcare and life saving technology on a global scale and beyond COVID-19.
基金National Natural Science Foundation of China(Grant No50578034)Shanghai Educational Development Foundationtitled"Shuguang Project"(Grant NO03SG30)
文摘Considering four different climate zones in China, an investigation on the choice of heat recovery ventilator for the buildings with little moisture emissions is carried out. The annual composition of energy consumption of air intake for per unitary air ventilation flow rate is evaluated by employing the testing data of climatic parameters in eight selected cities. The analysis shows that the total heat recovery is suitable in a controlled ventilation system with air humidity controlled during heating period of all the climates. For the building without air humidity controlled in winter, the sensible heat recovery ventilators can be used in severe cold and cold regions, and total heat recovery systems are more suitable for energy saving in hot summer and cold winter and hot summer and warm winter regions.
文摘BACKGROUND Patients with cancer have several risk factors for developing respiratory failure requiring mechanical ventilation(MV).The emergence of multidrug resistant bacteria(MDRB)has become a public health problem,creating a new burden on medical care in hospitals,particularly for patients admitted to the intensive care unit(ICU).AIM To describe risk factors for ventilator-acquired pneumonia(VAP)in patients with cancer and to evaluate the impact of MDRB.METHODS A retrospective study was performed from January 2016 to December 2018 at a cancer referral center in Mexico City,which included all patients who were admitted to the ICU and required MV≥48 h.They were classified as those who developed VAP versus those who did not;pathogens isolated,including MDRB.Clinical evolution at 60-d was assessed.Descriptive analysis was carried out;comparison was performed between VAP vs non-VAP and MDRB vs non-MDRB.RESULTS Two hundred sixty-three patients were included in the study;mean age was 51.9 years;52.1%were male;68.4%had solid tumors.There were 32 episodes of VAP with a rate of 12.2%;11.5 episodes/1000 ventilation-days.The most frequent bacteria isolated were the following:Klebsiella spp.[n=9,four were Extended-Spectrum Beta-Lactamase(ESBL)producers,one was Carbapenem-resistant(CR)];Escherichia coli(n=5,one was ESBL),and Pseudomonas aeruginosa(n=8,two were CR).One Methicillin-susceptible Staphylococcus aureus was identified.In multivariate analysis,the sole risk factor associated for VAP was length of ICU stay(OR=1.1;95%CI:1.03-1.17;P=0.003).Sixty-day mortality was 53%in VAP and 43%without VAP(P=0.342).There was not higher mortality in those patients with MDRB.CONCLUSION This study highlights the high percentage of Gram-negative bacteria,which allows the initiation of empiric antibiotic coverage for these pathogens.In this retrospective,single center,observational study,MDRB VAP was not directly linked to increased mortality at 60 days.
文摘Objective:To observe the application effect of non-invasive ventilator in the treatment of acute heart failure merged with respiratory failure in ICU.Methods:A total of 80 patients with acute heart failure merged with respiratory failure who were admitted in ICU from January, 2015 to January, 2016 were included in the study and randomized into the observation group and the control group with 40 cases in each group. The patients in the two groups were given routine treatments after admission. On this basis, the patients in the observation group were given non-invasive ventilator. The patients in the control group were given continuous low flow oxygen inhalation. PaO2, pH, PaCO2, SaO2, and PaO2/FiO2 before and after treatment between the two groups were compared. The serum NT-pro BNP and cTnI levels before treatment, 24 h and 48 h after treatment in the two groups were compared.Results:The comparison of PaO2, pH, PaCO2, SaO2, and PaO2/FiO2 before treatment between the two groups was not statistically significant. PaO2, pH, SaO2, and PaO2/FiO2 after treatment in the two groups were significantly elevated, while PaCO2 was significantly reduced when compared with before treatment. PaO2, pH, SaO2, and PaO2/FiO2 after treatment in the observation group were significantly higher than those in the control group, while PaCO2 was significantly lower than that in the control group. The comparison of NT-pro BNP and cTnI levels before treatment between the two groups was not statistically significant. NT-pro BNP and cTnI levels 12 h and 24 h after treatment in the two groups were significantly elevated when compared with before treatment. NT-pro BNP and cTnI levels 12 h and 24 h after treatment in the observation group were significantly lower than those in the control group.Conclusions:Non-invasive ventilator in the treatment of acute heart failure merged with respiratory failure can effectively improve the ventilation function, reduce NT-pro BNP and cTnI levels, and is of great significance in enhancing the rescued effect.
文摘This review, based on relevant published evidence and the authors` clinical experience, presents how to evaluate a patient with acute respiratory failure requiring ventilatory support. This patient must be carefully evaluated by nurses, physiotherapists, respiratory care practitioners and physicians regarding the elucidation of the cause of the acute episode of respiratory failure by means of physical examination with the measurement of respiratory parameters and assessment of arterial blood gases analysis to make a correct respiratory diagnosis. After the initial evaluation, the patient must quickly receive adequate oxygen and ventilatory support that has to be carefully monitored until its discontinuation. When available, a noninvasive ventilation trial must be done in patients presenting desaturation during oxygen mask and or PaCO2 retention, especially in cases of cardiogenic pulmonary edema and severe exacerbation of chronic obstructive pulmonary disease. In cases of noninvasive ventilation trial-failure, endotracheal intubation and invasive protective mechanical ventilation must be promptly initiated. In severe ARDS patients, low tidal ventilation, higher PEEP levels, prone positioning and recruitment maneuvers with adequate PEEP titration should be used. Recently, new modes of ventilation should allow a better patient-ventilator interaction or synchrony permitting a sufficient unloading of respiratory muscles and increase patient comfort. Patients with chronic obstructive pulmonary disease may be considered for a trial for early extubation to noninvasive positive pressure ventilation in centers with extensive experience in noninvasive positive pressure ventilation.
文摘Objective: To investigate the effect of Shenqi Fuzheng Injection combined with naloxone and BiPAP ventilator on serum inflammatory factors, immune function and blood gas analysis indexes in treatment of AECOPD with type Ⅱ respiratory failure. Methods: A total of 82 patients with AECOPD and type Ⅱ respiratory failure were divided into control group (n=40) and observation group (n=42) according to random data table, patients in the control group received naloxone and BiPAP ventilator therapy, and observation group patients were treated with Shenqi Fuzheng Injection on the basis of control group. The levels of serum inflammatory factors, immune function and blood gas analysis indexes were compared between the two groups before and after treatment. Results: There were no significant difference in levels of CRP, TNF-α, IL-6, CD3+, CD4+, CD8+, CD4+/CD8+, PaO2, PaCO2, SaO2 and pH before and after treatment in the two groups. After treatment, the levels of CRP, TNF-α, IL-6, CD8+and PaCO2 in two groups were significantly lower than those in same group before treatment, moreover observation group was significantly lower than control group;and levels of CRP, TNF-α, IL-6, CD8+ and PaCO2 in the observation group was significantly lower than those of the control group, the difference was statistically significant;When compared with the group before treatment, CD3+, CD4+, CD4+/CD8+, PaO2, SaO2 and pH levels of both groups after treatment were significantly increased, and the level of each index of observation group after treatment were significantly higher than the control group, the difference was statistically significant. Conclusion: The clinical effect of Shenqi Fuzheng Injection Combined with naloxone and BiPAP ventilator in treatment of AECOPD with type II respiratory failure is significant, can effectively reduce the body's inflammatory reaction, improve immune function, regulate blood gas analysis index, with a certain clinical value.
文摘Objective:To analyze the factors of flatulence in patients treated with non-invasive ventilator and summarize practical and effective nursing measures.Methods:From July 2020 to June 2021,40 patients who complained of flatulence after using non-invasive ventilator were analyzed.Results:20 cases of abdominal distension were caused by the habit of breathing with their mouth open,10 cases of abdominal distention were caused by liking to eat soup,10 cases of abdominal distention were caused by long-term bed-in-bed activity reduced gastrointestinal peristalsis constipation.Conclusion:We should investigate the causes causing gastrointestinal flatulence with the use of non-invasive ventilators,intervene in advance,boost patient comfort,collaborate with therapy,and improve the therapeutic result.
文摘A study was carried out to control the noise produced by the ventilators at the Luling coalmine, which had caused serious noise pollution to the residents living around the mine for a long time. The main noise source was found to be the dynamic noise at the outlet of the diffuser. The frequency of its peak value was 250 Hz. A special brick with a resonant frequency of 250 Hz was designed to eliminate this noise. The diffusion of a lower frequency noise has been successfully controlled by the installation of a noise-eliminating tower above the diffuser outlet. The detection results show that the noise in the nearby residential area has been lowered to an average 55.3dB(A) in the daytime from 69.8dB(A) and to 48.4dB(A) at night from 65.8dB(A).
